The present invention relates, in general, to a muffler and, more particularly, to a muffler for an internal combustion engine, capable of attenuating exhaust sound sufficiently and preventing power output from being reduced, by allowing exhaust gas to flow without a hitch and generating vortices.
As well known to those skilled in the art, since exhaust gas discharged from an exhaust manifold has a high temperature of 600 to 800xc2x0 C. and a high pressure of 3 to 5 kg/cm2, explosive sound occurs and fire may occur due to the abrupt expansion of the exhaust gas, when the exhaust gas is directly discharged from the exhaust manifold to the atmosphere. In order to overcome such problems, an exhaust inlet pipe is connected to the exhaust manifold and a muffler for an internal combustion engine is connected to the exhaust pipe, so that the temperature and the pressure of the exhaust gas are reduced, thereby attenuating the exhaust sound.
Various types of mufflers for an internal combustion engine are proposed. Of the mufflers, an expansion-type muffler and an expansion and resonator-type muffler are widely used. According to the expansion-type muffler, the interior of a casing is divided by a plurality of partitions so as to form a plurality of expansion chambers and the expansion chambers are in communication with each other through a plurality of conduits each having small diameters. Therefore, exhaust gas repeats expansion and acceleration, so that sound waves are interfered and the temperature and the pressure of the exhaust gas are reduced, thereby attenuating the exhaust sound. According to the expansion and resonator-type muffler, one of the expansion chambers of the expansion-type muffler is assigned to a resonance chamber. Therefore, in the expansion chamber the exhaust sound is attenuated in the same way as that of the expansion-type muffler, and in the resonance chamber the resonance of the sound wave of a specific frequency is suppressed, thereby attenuating the exhaust sound of the specific frequency.
However, according to the conventional mufflers, since the temperature and the pressure of the exhaust gas are reduced while exhaust gas passes through the expansion chambers and the conduits, large flow resistance occurs. When the large flow resistance occurs, sound attenuation is satisfactory, but back pressure, which is the resistance imposed on exhaust stroke, is increased.
Since the back pressure reduces volume efficiency by increasing the density of exhaust gas remaining in a combustion chamber, there occur problems in which power output is reduced and the quantity of consumed fuel is increased.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a muffler for an internal combustion engine, capable of attenuating exhaust sound sufficiently and preventing power output from being reduced, by allowing exhaust gas to flow without a hitch and generating vortices.
Another object of the present invention is to provide a muffler for an internal combustion engine, capable of reducing carbon smoke at low cost when diesel fuel is used as well as attenuating exhaust sound sufficiently and preventing power output from being reduced.
In order to accomplish the above object, the present invention provides a muffler for an internal combustion engine, comprising a casing, a vortex diffusing means mounted in the casing and connected to an exhaust inlet pipe, a vortex generating cylinder positioned in the casing at its first side and protruded into the exterior at its second side, and provided with a tail pipe at its exterior end, and a vortex generating member axially mounted in the vortex generating cylinder.
The present invention also provides a muffler for an internal combustion engine, comprising a casing, a vortex diffusing means mounted in the casing and connected to an exhaust inlet pipe, a vortex generating cylinder positioned in the casing at its first side and protruded into the exterior at its second side, and provided with a tail pipe at its exterior end, and a heater provided at the exterior end portion of the vortex generating cylinder.